Image source refactoring

src/ol/imagebase.js

@@ -0,0 +1,127 @@
+goog.provide('ol.ImageBase');
+goog.provide('ol.ImageState');
+
+goog.require('goog.events.EventTarget');
+goog.require('goog.events.EventType');
+goog.require('ol.Attribution');
+goog.require('ol.Extent');
+
+
+/**
+ * @enum {number}
+ */
+ol.ImageState = {
+  IDLE: 0,
+  LOADING: 1,
+  LOADED: 2,
+  ERROR: 3
+};
+
+
+
+/**
+ * @constructor
+ * @extends {goog.events.EventTarget}
+ * @param {ol.Extent} extent Extent.
+ * @param {number} resolution Resolution.
+ * @param {number} pixelRatio Pixel ratio.
+ * @param {ol.ImageState} state State.
+ * @param {Array.<ol.Attribution>} attributions Attributions.
+ */
+ol.ImageBase = function(extent, resolution, pixelRatio, state, attributions) {
+
+  goog.base(this);
+
+  /**
+   * @private
+   * @type {Array.<ol.Attribution>}
+   */
+  this.attributions_ = attributions;
+
+  /**
+   * @private
+   * @type {ol.Extent}
+   */
+  this.extent_ = extent;
+
+  /**
+   * @private
+   * @type {number}
+   */
+  this.pixelRatio_ = pixelRatio;
+
+  /**
+   * @private
+   * @type {number}
+   */
+  this.resolution_ = resolution;
+
+  /**
+   * @protected
+   * @type {ol.ImageState}
+   */
+  this.state = state;
+
+};
+goog.inherits(ol.ImageBase, goog.events.EventTarget);
+
+
+/**
+ * @protected
+ */
+ol.ImageBase.prototype.dispatchChangeEvent = function() {
+  this.dispatchEvent(goog.events.EventType.CHANGE);
+};
+
+
+/**
+ * @return {Array.<ol.Attribution>} Attributions.
+ */
+ol.ImageBase.prototype.getAttributions = function() {
+  return this.attributions_;
+};
+
+
+/**
+ * @return {ol.Extent} Extent.
+ */
+ol.ImageBase.prototype.getExtent = function() {
+  return this.extent_;
+};
+
+
+/**
+ * @param {Object=} opt_context Object.
+ * @return {HTMLCanvasElement|Image|HTMLVideoElement} Image.
+ */
+ol.ImageBase.prototype.getImageElement = goog.abstractMethod;
+
+
+/**
+ * @return {number} PixelRatio.
+ */
+ol.ImageBase.prototype.getPixelRatio = function() {
+  return this.pixelRatio_;
+};
+
+
+/**
+ * @return {number} Resolution.
+ */
+ol.ImageBase.prototype.getResolution = function() {
+  return this.resolution_;
+};
+
+
+/**
+ * @return {ol.ImageState} State.
+ */
+ol.ImageBase.prototype.getState = function() {
+  return this.state;
+};
+
+
+/**
+ * Load not yet loaded URI.
+ */
+ol.ImageBase.prototype.load = goog.abstractMethod;